What does "move to junk and blacklist email" actually means?

When you choose “move to junk” you get three options:

  • move to junk
  • move to junk and blacklist email
  • move to junk and blacklist domain

What is meant by “blacklist email”? Is that blacklisting email address? Or more features the email has? If it’s only email address it should say so, because it’s confusing otherwise.

Yes. The sender’s email address is added to the Blacklist, and any future messages from that address will be moved to Junk.

There are two options; blacklisting the address or the domain.